The Cell Biology Program investigates the fundamental mechanisms that control key cellular functions such as transformation, proliferation, survival, differentiation, migration and invasion. It is based on the concept that fundamental research on mechanisms that control cell behavior and how they are altered in malignant cells, will lead to the identification of new targets for cancer prevention, diagnosis or treatment in the Cancer Center is an ideal platform to promote the translation of fundamental discoveries to preclinical and clinical trials. The program consists of 34 independently funded principal investigators organized in four sections who have been successful in generating 390 publications between 1995 and 1999, and more than $8.7 million in NIH funding. The "Extracellular Matrix" Section seeks to understand how ECM proteins and their modification by proteolysis influences cell growth and survival and to explore novel approaches to inhibit angiogenesis. The "Signaling" section focuses on the molecular mechanisms of the ABR/BCL oncogene in Philadelphia positive leukemia, on the interaction of small GTPases with nucleotide exchange factors, and on kinases and phosphatases in cell cycle control. The "Tumor Immunology" section seeks the understanding of the mechanisms of tumor rejection, of the role of ADP ribosyltransferase in CTL and of thymic ontogeny. The "Developmental Biology" section focuses on genes involved in neural crest, bone, lung and mammary development and their involvement in malignant transformation. Interaction among the members of the Program and with members of other programs in the Cancer Center is promote by a series of Cancer Center is promoted by a series of Cancer Center sponsored activities including monthly section meets, participation in weekly Cancer Center Grant Rounds, minisymposia and a biannual program retreat. Goals for the development of the Program include a growing scientific emphasis in the area of angiogenesis, , integrin signaling and tumor immunology and continuing efforts to test basic observations at a preclinical and clinical level.